Camera Lens

ABSTRACT

A camera lens includes, arranged sequentially from an object side to an image side: a first lens with positive refractive power; a second lens with negative refractive power; a third lens with positive refractive power; fourth lens with positive refractive power; and a fifth lens with negative refractive power. The camera lens satisfies specific conditions.

FIELD OF THE PRESENT DISCLOSURE

The present disclosure relates to the technical field of camera lens.

DESCRIPTION OF RELATED ART

In recent years, various camera devices equipped with camera elementssuch as CCD, CMOS are extensively popular. Along with development oncamera lens toward miniaturization and high performance, ultra-thincamera lenses with excellent optical properties and with chromaticaberration sufficiently corrected are needed in society.

The technology related to the camera lens composed of five pieceultra-thin lenses with excellent optical properties and with chromaticaberration sufficiently corrected is developed gradually. The cameralens mentioned in the proposal is composed of five piece lenses whichare arranged sequentially from the object side as follows: a first lenswith positive refractive power; a second lens with negative refractivepower; a third lens with positive refractive power; a fourth lens withpositive refractive power and a fifth lens with negative refractivepower.

The camera lens disclosed in embodiment of the prior Japanese Patent No.5513648 is mentioned above and it is composed of five piece lenses, butrefractive power distribution of the first and the third lens isinsufficient and shape of the first lens is improper; TTL/LH≧1.64 so itis not sufficiently ultra-thin.

The camera lens disclosed in embodiments of prior Japanese PatentPublication No. 2015-225246 is mentioned above and is composed of fivepiece lenses, but refractive power distribution of the second lens andthe third lens is insufficient, so it is insufficiently untra-thin.Thereof, it is necessary to disclose and provide an improved camera toovercome the above-mentioned disadvantages.

Therefore, an improved camera lens which can overcome the disadvantagesmentioned above is desired.

BRIEF DESCRIPTION OF THE DRAWING

Many aspects of the exemplary embodiments can be better understood withreference to the following drawing. The components in the drawing arenot necessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present disclosure.

FIG. 1 is a structure diagram of a camera lens LA related to oneembodiment of the invention.

FIG. 2 is a structure diagram of the definite Embodiment 1 of theabove-mentioned camera lens LA.

FIG. 3 is the spherical aberration diagram of the camera lens LA inEmbodiment 1.

FIG. 4 is the magnification chromatic aberration diagram of the cameralens LA in Embodiment 1.

FIG. 5 is the image surface curving diagram and distortion aberrationdiagram of the camera lens LA in Embodiment 1.

FIG. 6 is the structure diagram of the definite Embodiment 2 of theabove-mentioned camera lens LA.

FIG. 7 is the spherical aberration diagram of the camera lens LA inEmbodiment 2.

FIG. 8 is the magnification chromatic aberration diagram of the cameralens LA in Embodiment 2.

FIG. 9 is the image surface curving diagram and distortion aberrationdiagram of the camera lens LA in Embodiment 2.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The present disclosure will hereinafter be described in detail withreference to exemplary embodiments. To make the technical problems to besolved, technical solutions and beneficial effects of the presentdisclosure more apparent, the present disclosure is described in furtherdetail together with the figure and the embodiments. It should beunderstood the specific embodiments described hereby are only to explainthe disclosure, not intended to limit the disclosure.

FIG. 1 is the structure diagram of a camera lens LA related to oneembodiment of the invention. The camera lens LA is composed of fivepiece lenses which are arranged sequentially from the object side to theimaging surface side including a first lens L1, a second lens L2, athird lens L3, a fourth lens L4, a fifth lens L5. A glass plate GF isarranged between the fifth lens L5 and the imaging surface. And a glasscover or an optical filter having the function of filtering IR can betaken as the glass plate GF. Moreover, it shall be fine if no glassplate GF is arranged between the fifth lens L5 and the imaging surface.

The first lens L1 has positive refractive power; the second lens L2 hasnegative refractive power; the third lens L3 has positive refractivepower; the fourth lens L4 has positive refractive power; the fifth lensL5 has negative refractive power. Moreover, the surfaces of the fivelenses should be designed as the aspheric shape preferably in order tocorrect the aberration well.

A camera lens is characterized in that the camera lens meets followingconditions (1)˜(5):

0.65≦f1/f≦0.75  (1)

−1.40≦f2/f≦−1.25  (2)

10.00≦f3/f≦24.00  (3)

−1.20≦(R1+R2)/(R1−R2)≦−1.00  (4)

1.00≦(R3+R4)/(R3−R4)≦2.00  (5)

where,f: overall focal distance of the camera lensf1: focal distance of the first lensf2: focal distance of the second lensf3: focal distance of the third lensR1: curvature radius of the first lens' object side surfaceR2: curvature radius of the first lens' image side surfaceR3: curvature radius of the second lens' object side surfaceR4: curvature radius of the second lens' image side surface

The positive refractive power of the first lens L1 is specified in thecondition (1). When exceeding lower limit of condition (1), the firstlens L1's positive refractive power is too strong to correct aberration.On the contrary, when exceeding upper limit of condition (1), the firstlens L1's refractive power is too week to develop toward ultra-thin.

Therefore, numerical range of condition (1) should be set within thenumerical range of the following condition (1-A) preferably,

0.72≦f1/f≦0.75  (1-A)

Negative refractive power of the second lens L2 is specified in thecondition (2). Moreover, chromatic aberration on axle and outside ofaxle cannot be corrected easily along with development toward ultra-thinoutside the range of the condition (2).

Therefore, numerical range of condition (2) should be set within thenumerical range of the following condition (2-A) preferably,

−1.38≦f2/f≦≦−1.28  (2-A)

The positive refractive power of the third lens L3 is specified in thecondition (3). Moreover, chromatic aberration on axle and outside ofaxle cannot be corrected easily along with development toward ultra-thinoutside the range of the condition (3).

Therefore, numerical range of condition (3) should be set within thenumerical range of the following condition (3-A) preferably,

15.00≦f3/f≦20.00  (3-A)

The shape of the first lens L1 is specified in the condition (4).Moreover, the problems of high order aberration such as aberration ofspherical surface cannot be corrected easily along development towardultra-thin trend outside the range of the condition (4)

Therefore, numerical range of condition (4) should be set within thenumerical range of the following condition (4-A) preferably,

−1.15≦(R1+R2)/(R1−R2)≦−1.05  (4-A)

Shape of the second lens L2 is specified in the condition (5). Moreover,chromatic aberration on axle cannot be corrected easily along withdevelopment toward ultra-thin trend outside the range of the condition(5).

Therefore, numerical range of condition (5) should be set within thenumerical range of the following condition (5-A) preferably,

1.10≦(R3+R4)/(R3−R4)≦1.50  (5-A)

The fourth lens L4 has positive refractive power and meets the followingcondition (6).

0.50≦f4/f≦0.72  (6)

where,f: overall focal distance of the camera lensf4: focal distance of the fourth lens

The positive refractive power of the fourth lens L4 is specified in thecondition (6). Within the range of the condition (3), chromaticaberration on axle and outside of axle can be corrected sufficiently, sodevelopment toward ultra-thin trend is effective.

Therefore, numerical range of condition (6) should be set within thenumerical range of the following condition (6-A) preferably,

0.55≦f4/f≦0.60  (6-A)

Because five piece lenses of camera Lens LA all have the statedformation and meet all the conditions, so it is possible to produce anultra-thin camera lens with excellent optical properties and withchromatic aberration sufficiently corrected.

EMBODIMENTS

f: overall focal distance of the camera lens LAf1: focal distance of the first lens L1f2: focal distance of the second lens L2f3: focal distance of the third lens L3f4: focal distance of the fourth lens L4f5: focal distance of the fifth lens L5

Fno: F Value

2ω: total angle of viewS1: Open apertureR: curvature radius of optical surface, if a lens is involved it iscentral curvature radiusR1: curvature radius of the first lens L1's object side surfaceR2: curvature radius of the first lens L1's image side surfaceR3: curvature radius of the second lens L2's object side surfaceR4: curvature radius of the second lens L2's image side surfaceR5: curvature radius of the third lens L3's object side surfaceR6: curvature radius of the third lens L3's image side surfaceR7: curvature radius of the fourth lens L4's object side surfaceR8: curvature radius of the fourth lens L4's image side surfaceR9: curvature radius of the fifth lens L5's object side surfaceR10: curvature radius of the fifth lens L5's image side surfaceR11: curvature radius of the glass plate GF's object side surfaceR12: curvature radius of the glass plate GF's image side surfaced: center thickness of lenses or the distance between lensesd0: axial distance from open aperture S1 to object side surface of thefirst lens L1d1: center thickness of the first lens L1d2: axial distance from image side surface of the first lens L1 toobject side surface of the second lens L2d3: center thickness of the second lens L2d4: axial distance from image side surface of the second lens L2 toobject side surface of the third lens L3d5: center thickness of the third lens L3d6: axial distance from image side surface of the third lens L3 toobject side surface of the fourth lens L4d7: center thickness of the fourth lens L4d8: axial distance from image side surface of the fourth lens L4 toobject side surface of the fifth lens L5d9: center thickness of the fifth lens L5d10: axial distance from image side surface of the fifth lens L5 toobject side surface of the glass plate GFd11: center thickness of glass plate GFd12: axial distance from image side surface to imaging surface of theglass plate GFnd: refractive power of line dnd1: refractive power the first lens L1's line dnd2: refractive power the second lens L2's line dnd3: refractive power the third lens L3's line dnd4: refractive power the fourth lens L4's line dnd5: refractive power the fifth lens L5's line dnd6: refractive power the glass plate GF's line dνd: abbe numberν1: abbe number of the first lens L1ν2: abbe number of the second lens L2ν3: abbe number of the third lens L3ν4: abbe number of the fourth lens L4ν5: abbe number of the fifth lens L5ν6: abbe number of the glass plate GFTTL: optical length (axial distance from object side surface to theimaging surface of the first lens L1)LB: axial distance (including thickness of the glass plate GF) from theimage side surface to the imaging surface of the fifth lens L5;IH: Image height

y=(×2/R)/[1+{1−(k+1)(×2/R2)}1/2]+A4×4+A6×6+A8×8+A10×10+A12×12+A14×14+A16×16  (7)

where, R is axial curvature radius, k is cone coefficient, A4, A6, A8,A10, A12, A14, A16 are aspheric coefficients.

For convenience sake, the aspheric surface shown in the formula (7)shall be taken as the aspheric surfaces of all lens' surfaces. However,the invention shall not be limited to polynomial form of the asphericsurface shown in the formula (7).

Embodiment 1

FIG. 2 is the structure of camera lens LA in Embodiment 1. Data shown inTable 1: curvature radius R of the object side surfaces and the imageside surfaces, center thicknesses of the lenses, distances d among thelenses, refractive powers nd and abbe numbers of the lens L1˜L5 in theEmbodiment 1, wherein the camera lens LA is formed by the lens L1˜L5;Data shown in Table 2: conical coefficients k and aspheric coefficients

TABLE 1 R d nd vd S1 ∞ d0 = −0.240 R1 1.44850 d1 = 0.584 nd1 1.5441 v156.12 R2 32.12183 d2 = 0.066 R3 54.55574 d3 = 0.229 nd2 1.6510 v2 21.51R4 3.10456 d4 = 0.256 R5 8.45509 d5 = 0.285 nd3 1.6510 v3 21.51 R610.26819 d6 = 0.422 R7 −4.28228 d7 = 0.697 nd4 1.5441 v4 56.12 R8−0.99491 d8 = 0.287 R9 −4.76436 d9 = 0.400 nd5 1.5441 v5 56.12 R101.38204 d10 = 0.400 R11 ∞ d11 = 0.210 nd6 1.5168 v6 64.17 R12 ∞ d12 =0.584

TABLE 2 Cone coefficiente Aspheric coefficient k A4 A6 A8 A10 A12 A14A16 R1 4.8003E−02 −7.5918E−03 3.5652E−02 −1.0513E−01 1.2134E−01−1.0049E−02 −1.0371E−01 2.2482E−02 R2 −6.7536E+03 2.1292E−02 −5.3298E−021.3170E−01 −1.8270E−01 −1.6671E−01 −8.6935E−03 1.8588E−01 R3 1.8571E+03−5.3194E−03 8.5520E−02 1.6080E−04 −8.9682E−02 −1.8983E−01 −2.5603E−014.7318E−01 R4 −2.5626E+00 4.3404E−03 7.6463E−02 1.5064E−01 −1.5666E−01−2.1649E−01 2.3483E−01 4.4136E−03 R5 −1.8882E+02 −1.0043E−01 −8.3201E−024.5277E−02 2.5798E−01 −1.9496E−01 8.5177E−02 −8.2722E−02 R6 −1.2379E+033.2534E−02 −3.1415E−01 4.8723E−01 −3.7818E−01 1.7728E−01 1.9176E−02−2.8905E−02 R7 5.3809E+00 1.7497E−02 3.9520E−02 −6.2179E−02 1.8174E−023.8736E−03 −8.0599E−04 −2.1425E−04 R8 −4.1555E+00 −1.1248E−01 1.3304E−01−6.8661E−02 2.0277E−02 −2.3873E−03 −4.8760E−04 1.0320E−04 R9 3.1156E+00−5.9806E−02 1.8884E−02 1.9826E−03 −1.0972E−03 7.6838E−05 1.3360E−05−1.4973E−06 R10 −1.0009E+01 −8.6727E−02 3.8617E−02 −1.4510E−023.5897E−03 −5.5425E−04 4.5156E−05 −1.2654E−06

The values in embodiment 1 and 2 and the values corresponding to theparameters specified in the conditions (1)˜(6) are shown in subsequentTable 5.

As shown on Table 5, the Embodiment 1 meets the conditions (1)˜(6).

Spherical aberration of camera lens LA in embodiment 1 is shown in FIG.3, magnification chromatic aberration of the same is shown in FIG. 4,image surface curving and distortion aberration of the same is shown inFIG. 5. Furthermore, image surface curving S in FIG. 5 is the oneopposite to the sagittal image surface, T is the one opposite to thetangent image surface. Same applies for the Embodiment 2. As show inFIG. 3˜5, the camera lens in embodiment 1 has the properties as follows:TTL/IH=1.506 ultra-thin, its chromatic aberration is sufficientlycorrected, so it is not hard to understand why it has excellent opticalproperties.

Embodiment 2

FIG. 6 is the structure of camera lens LA in Embodiment 2. Data shown inTable 3: curvature radius R of the object side surfaces and the imageside surfaces, center thicknesses of the lenses, distances d among thelenses, refractive powers nd and abbe numbers of the lens L1˜L5 in theEmbodiment 2, wherein the camera lens LA is formed by the lens L1˜L5;Data shown in Table 4: and the data including conical coefficients k andaspheric coefficients

TABLE 3 R d nd vd S1 ∞ d0 = −0.240 R1 1.44941 d1 = 0.584 nd1 1.5441 v156.12 R2 42.65272 d2 = 0.066 R3 56.62268 d3 = 0.229 nd2 1.6510 v2 21.51R4 3.07803 d4 = 0.260 R5 8.59276 d5 = 0.286 nd3 1.6510 v3 21.51 R610.34641 d6 = 0.425 R7 −4.25372 d7 = 0.710 nd4 1.5441 v4 56.12 R8−0.99634 d8 = 0.285 R9 −4.75532 d9 = 0.400 nd5 1.5441 v5 56.12 R101.37617 d10 = 0.400 R11 ∞ d11 = 0.210 nd6 1.5168 v6 64.17 R12 ∞ d12 =0.590

TABLE 4 Cone coefficiente Aspheric coefficient k A4 A6 A8 A10 A12 A14A16 R1 5.0143E−02 −7.4011E−03 3.5871E−02 −1.0517E−01 1.2108E−01−1.0456E−02 −1.0419E−01 2.2038E−02 R2 −1.0486E+04 2.0797E−02 −5.3045E−021.3206E−01 −1.8277E−01 −1.6751E−01 −1.0205E−02 1.8390E−01 R3 2.0224E+03−4.6215E−03 8.5508E−02 −3.1859E−04 −9.0324E−02 −1.9066E−01 −2.5725E−014.7130E−01 R4 −2.7761E+00 3.5769E−03 7.5894E−02 1.5097E−01 −1.5639E−01−2.1687E−01 2.3365E−01 2.8077E−03 R5 −1.9806E+02 −1.0060E−01 −8.3226E−024.5151E−02 2.5768E−01 −1.9528E−01 8.5138E−02 −8.2259E−02 R6 −1.1456E+033.3076E−02 −3.1336E−01 4.8750E−01 −3.7841E−01 1.7696E−01 1.9041E−02−2.8810E−02 R7 5.3681E+00 1.7799E−02 3.9502E−02 −6.2298E−02 1.8127E−023.8704E−03 −8.0092E−04 −2.1225E−04 R8 −4.1782E+00 −1.1224E−01 1.3303E−01−6.8678E−02 2.0278E−02 −2.3823E−03 −4.8230E−04 1.0687E−04 R9 3.1027E+00−5.9804E−02 1.8895E−02 1.9847E−03 −1.0968E−03 7.6922E−05 1.3376E−05−1.4888E−06 R10 −9.9826E+00 −8.6960E−02 3.8572E−02 −1.4511E−023.5903E−03 −5.5416E−04 4.5160E−05 −1.2662E−06

As shown on Table 5, the Embodiment 2 meets the conditions (1)˜(6).

Spherical aberration of camera lens LA in embodiment 2 is shown in FIG.7, magnification chromatic aberration of the same is shown in FIG. 8,image surface curving and distortion aberration of the same is shown inFIG. 9. As show in FIG. 7˜9, the camera lens in embodiment 2 has theproperties as follows: TTL/IH=1.515 ultra-thin, its chromatic aberrationis sufficiently corrected, so it is not hard to understand why it hasexcellent optical properties.

The values in all embodiments and the values corresponding to theparameters specified in the conditions (1)-6 are shown in the Table 5.Furthermore, unit of various values in Table 5 is respectively 2ω(°), f(mm), f1 (mm), f2 (mm), f3 (mm), f4 (mm), f5 (mm), f6 (mm), TTL (mm), LB(mm), IH (mm).

TABLE 5 Embodiment 1 Embodiment 2 Condition f1/f 0.741 0.731 1 f2/f−1.355 −1.335 2 f3/f 18.530 19.497 3 (R1 + R2)/(R1 − R2) −1.094 −1.070 4(R3 + R4)/(R3 − R4) 1.121 1.115 5 f4/f 0.593 0.592 6 Fno 2.20 2.20 2ω75.4 74.9 TTL/IH 1.506 1.515 f 3.738 3.753 f1 2.769 2.744 f2 −5.066−5.009 f3 69.265 73.174 f4 2.216 2.220 f5 −1.925 −1.917 TTL 4.420 4.445LB 1.194 1.200 IH 2.934 2.934

It is to be understood, however, that even though numerouscharacteristics and advantages of the present exemplary embodiments havebeen set forth in the foregoing description, together with details ofthe structures and functions of the embodiments, the disclosure isillustrative only, and changes may be made in detail, especially inmatters of shape, size, and arrangement of parts within the principlesof the invention to the full extent indicated by the broad generalmeaning of the terms where the appended claims are expressed.

What is claimed is:
 1. A camera lens comprising, arranged sequentially from an object side to an image side: a first lens with positive refractive power; a second lens with negative refractive power; a third lens with positive refractive power; a fourth lens with positive refractive power; a fifth lens with negative refractive power; wherein the camera lens satisfies the following conditions (1)˜(5): 0.65≦f1/f≦0.75  (1) −1.40≦f2/f≦−1.25  (2) 10.00≦f3/f≦24.00  (3) −1.20≦(R1+R2)/(R1−R2)≦−1.00  (4) 1.00≦(R3+R4)/(R3−R4)≦2.00  (5) where, f: overall focal distance of the camera lens; f1: focal distance of the first lens; f2: focal distance of the second lens; f3: focal distance of the third lens; R1: curvature radius of the first lens' object side surface; R2: curvature radius of the first lens' image side surface; R3: curvature radius of the second lens' object side surface; R4: curvature radius of the second lens' image side surface.
 2. The camera lens as described in claim 1 further satisfying the following condition (6): 0.50≦f4/f≦0.72  (6) where, f: overall focal distance of the camera lens; f4: focal distance of the fourth lens. 